Heretofore, wheel bearing devices for automobiles have been combined with a rotational speed detecting mechanism for detecting the rotational speed of a wheel, for use in controlling an antilock brake system (ABS), a traction control system (TCS), or the like. The rotational speed detecting mechanism comprises a magnetic ring or the like mounted on a rotary member, which is rotatable in unison with the wheel and having magnetic characteristics that vary periodically in the circumferential direction, and a rotational speed sensor mounted on a fixed member that is fixed to the vehicle body. The magnetic ring or the like is attached to an inner member (inner ring) of the wheel bearing device, and the rotational speed sensor is attached to an outer member (outer ring) thereof.
Patent Documents 1 through 5 disclose technical concepts, wherein the magnetic ring is integrally combined with a hub bearing, taking into account replacement efficiency and the installation space.
Heretofore, a seal member has been provided for preventing water or the like from entering into the hub bearing. Patent Documents 1 through 5 take into account not only the positional relationship between the magnetic ring and the rotational speed sensor, but also the sealability of the hub bearing.
Patent Documents 6 through 8 disclose technical concepts related to using various seal members for increasing the sealability of the hub bearing.
Patent Document 9 reveals a constant velocity universal joint that is rotatably supported by a hub bearing on a knuckle member mounted on a vehicle body, and a seal structure disposed between the knuckle member and the hub bearing. It is mentioned that the seal structure prevents rainwater, for example, from entering into the hub bearing when the constant velocity universal joint and the hub rotate.
Patent Document 1: Japanese Laid-Open Patent Publication No. 3-279061
Patent Document 2: Japanese Laid-Open Patent Publication No. 6-308145
Patent Document 3: Japanese Laid-Open Patent Publication No. 2001-83166
Patent Document 4: Japanese Laid-Open Patent Publication No. 2000-221203
Patent Document 5: Japanese Laid-Open Patent Publication No. 2004-132782
Patent Document 6: Japanese Laid-Open Patent Publication No. 2001-294011
Patent Document 7: Japanese Laid-Open Patent Publication No. 2002-172912
Patent Document 8: Japanese Laid-Open Patent Publication No. 2003-175701
Patent Document 9: Japanese Laid-Open Utility Model Publication No. 63-133641